Beta doc for WS API 2.0 (Spring WS) is online at SourceForge. It covers 5 subscriber methods, but a "bulk subscribe" is not among them (see chapter 3).

WS API 1.0 (Apache Axis) is NOT deprecated and we will maintain it for some years at least. If you want to contribute a new method please feel free to provide the code (you can send me a PM is you like) and we will give you credit in the changelog file.